This paper reports a reliable passive micro pump system combining the physical properties of a tapered microchannel and sharp microstructures. This tailored micro, channel with triple-spike microstructures was created to transport condensed liquid into the reservoir chamber in a micro cooling device and in the case of chip off-mode prepare the next cooling cycle before chip on-mode, allowing the reliable and continuous circulation of coolant without liquid being trapped in the vapor channel causing dryout limitation. At the tapered channel end, the pinned liquid meniscus was distributed by a middle spike and then continued to,overflow into the condenser chamber due to extended capillary action.